Berton



F. BELYAVIN AND 0. e. ROBERTON.

SCAVENGING OF INTERNAL COMBUSTIONENGINES.

APPLICATION FILED Aue.s, I917.

Patented May 205 1919 UNITED STATES PATENT OFFICE,

PAUL BELYAVIN,

OF PETROGRAD, RUSSIA, AND CHARLES GEORGE ROBERTON, OF

BARROW-IN-FURNESS, ENGLAND. v

SCAVENGING OF INTERNAL-COMBUSTION ENGINES.

To all whom it may concern:

Be it known that we, PAUL BELYAVIN, a Russian-citizen, and CHARLES GEORGE Ro- BERTON, a subject of the King of Great Britain, residing, respectively, at 57 Officerskaya street, Petrograd, Russia, and Naval Construction Works, Barrow-in-Furness, 1n the county of Lancaster, England, have 1n vented certain new and useful Improvements in or Relating to the scavenging of Internal-Combustion Engines,'of which the following is a specification.

This invention relates to the scavenging of internal combustion. engines of the twostroke type and has for its chief ob ect to provide means by which the products of combustion can be displaced by the entering air and driven through the exhaust ports in front of the air without substantial admixture.

According to this invention the air and exhaust ports are placed at the same side of the cylinder and the air ports are so formed and disposed as to direct the incoming air diagonally to the opposite upper corner of the cylinder, the exhaust gases being displaced diagonally from this corner in a reverse direction toward the exhaust. A complete sweeping out of the products of combustion is effected by this means,"with only a small loss of air, since as soon as the stream of incoming air reaches the corner of the cylinder the displacement of the gases'proceeds from a point at maximum distance from the exhaust ports and the air drives the gases before it in a diagonal direction until the air fills the cylinder space. In the construction preferred the air ports are placed above the exhaust ports and may be of considerably smaller cross section, the air channels being of substantial length so as to give the necessary direction to the streams of air as they enter the cylinder. y

In order that the said invention may be clearly understood, and readily carried into efi'ect, the same will now be described more fully with reference to the accompanying drawings, in which Figure 1 is a vertical section of an engine cylinder illustrating the present method of scavenging; and

Figs. 2 and 3 are sectional planstaken respectively through the air inlet and the exhaust ports of the cylinder.

Specification of Letters Patent. Patented May 20, 1919. Application filed August 8, 1917. Serial No. 185,221. I

- A is the cylinder with cover a. B is the piston. C, C are the air inlet ports. D is the air inlet valve in the valve casingd- E, E are the exhaust p0rts in the exhaust casing e situated immediately below the valve casing d.

As shown in Fig. 2 three air inlet ports C are employed, the two outer ports being curved round so that the three entering streams of air are directed toward the same point a: at the opposite corner of the cylinder immediately inside the cover a; The number of ports 0 employed would depend upon the size of cylinder. The air channels are of substantial length and are all directed upwardly as shown in Fig. l, and when the inlet valve D is opened, shortly after the piston B begins to uncover the exhaust ports E, the air from the main 03' assing into the sloping air channels is directed upwardly and across the cylinder as shown by the arrows, driving the exhaust gases on each side of the entering streams diagonally toward the ports E in a steady flow. The air valve is arranged to close as soon as the cylinder space is filled with the air, only a small part of the exhaust gases remaining in mix ture with the air.

.The clearance space in the valve casing between the valve D and cylinder should be as small as possible consistent with the free passage of the entering air, as the inlet "ports are uncovered by the piston while the side of the cylinder whilethe air ports are made'narrower, but th'e proportions of the various ports and the relative positions may be varied according to the requirements of the engine.

That we claim' and desire to secure by Letters Patent of the United States is 1. Means for scavenging the cylinder of a two-stroke internal combustion engine, comprising air admission and exhaust ports placed at the same side of the cylinder, the said air admission ports being. so formed and disposed as to direct the incoming air diagonally to the opposite upper corner of the cylinder and to displace the exhaust gases diagonally from this corner in a reverse direction toward the exhaust, for the purpose specified.

2. In a two stroke internal combustion engine, a cylinder, exhaustports in the cylinder walls at one side and air inlet ports placedabove the said exhaust ports at the same side of the cylinder and inclined n1 wardly so as to direct the incoming air diagonally to the upper opposite corner of the cylinder, and to" displace the exhaust gases diagonally from this corner in a reverse direction toward the exhaust, for the 10 purpose specified.

8. In a two stroke internal combustion enweenie gine, a cylinder, exhaust ports at one side of the cylinder, an air inlet easing above the said exhaust ports and at the same side of the cylinder, an air admission valve in the said casing and. upwardly directed air inlet ports leading from the casing into the cylinder, for the'purpose specified.

In testimony whereof we afiix our signatures.

PAUL BELYAVIN. CHARLES GEORGE ROBERTQN. 

